Lecture Marine environmental studies Topic Ballast water
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BALLAST WATER
Gohoho Emmanuel Sena
Ballast Water
Necessary to maintain the trim and
stability of oceangoing vessels
What is Ballast?
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Ballast is anything used to weight and balance an object.
Ships use ballast to maintain balance, stability and structural integrity of
the hull.
Ballast water…
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In the past, ships used solids as ballast; this included metals, sand and
rocks.
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Today, ships use sea water as ballast and it is referred to as ballast water.
AQUATIC INVASIVE SPECIES (AIS)
Ballast Water and AIS
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As a result, ships and mariners have unintentionally transferred organisms from one
environment to another through the ballast water and sediments
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Species are introduced with ballast water discharge in recipient regions
What are AIS?
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Aquatic Invasive Species (AIS) are organisms transported by human activities to a
region where they did not occur historically and have established reproducing
populations in the wild.
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Also known as invasive,
exotic, alien, introduced,
aquatic nuisance species (ANS),
nonindigenous species (NIS),
non-native
Additional Facts
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Non-native species are considered the second greatest threat to biodiversity after habitat
destruction
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Many non-native species are capable of causing significant ecological, economic or human health
impacts
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In the marine environment, the rate of new introductions has increased exponentially during the
last 200 years
Example: Overbite Clam
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Corbula amurensis
Detected in SF Bay in 1986
Native to Asia
Very high feeding/filtration rate
Decline in copepod species associated
with spread of clam, may be associated
with decline of Delta smelt
Ballast Water and AIS
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Approximately 7000 species transported around the world each day in ballast water of ships
Volume of global trade is increasing = more ballast water (and species) in movement
Speed of global trade is increasing = more species survive transit
Examples of species introduced to SF Bay as a result of ballast water discharge:
Tridentiger barbatus
Palaemon macrodactylus
Philine auriformis
Vessel Fouling
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Community of organisms that attach
or associate with submerged portions
of structures
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On vessels, highest density in “niche”
areas: sea chests, around rudder, dry
dock strips
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13
Fouling and AIS
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Species introduced when organisms fall/drop off structures or spawn
(reproduce)
EFFECTS OF TRANSFER
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Ecological
Economic
Human health effects
Ecological Effects
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The AIS are introduced in some cases on a daily basis. When they
become established, they disrupt the native ecology and their presence
cannot be reversed.
Eg.
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A non-pacific Sea-star that was introduced in Australian waters threatened
commercial shell fish stock like scallops, and in just one estuary in
Tasmania, it reached a population of 30 million
Economic Effects
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The invasive organisms tend to threaten commercial activities like fishing,
coastal resources and industrial activities.
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In the USA, an average amount of $1.8 billion is spent on invasive
species annually.
Eg.
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The Zebra mussel which has been transferred into North American
Waters, has invaded inland water ways including industrial water uptakes.
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Between 1999 and 2000, the USA spent
$750 million - $1 Billion on the Zebra Mussel alone.
Zebra Mussel
Human Health Effects
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Pathogens and diseases are also carried by ballast water
The dinoflagellates (single-celled marine life) can release toxins which
can bloom into red tides and can be absorbed by shell fish. When
consumed by humans, this can cause paralysis or even death
How do they get here?
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Many mechanisms (vectors) capable of transporting AIS around the world
Aquaculture, live seafood shipments, bait, pet store trade, intentional
release
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Commercial ships responsible for up to 80% of introductions in coastal
habitats
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Includes ballast water and vessel fouling
Dealing with Ballast Water
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The problem of invasive species is not a pollution problem only, it is also a
problem of biodiversity.
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Hence, a convention on ballast water management has been adopted to
deal with the problem…
International Convention for the Control and Management of Ships' Ballast Water
and Sediments (BWMC)
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A diplomatic conference from 9 to13 February 2004 adopted this convention to prevent
the potentially devastating effects of the spread of harmful aquatic organisms carried by
ships' ballast water
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The Convention will require all ships
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To implement a Ballast Water and Sediments Management Plan.
To carry a Ballast Water Record Book
To carry out ballast water management procedures to a given standard.
Ratification status
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The BWMC will come into force one year after ratification by at least 30 States
comprising 35% of the world’s total gross tonnage.
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As of 12th January 2015, 44 States representing 32.86% out of the requisite
35% of the world’s merchant tonnage have ratified the Convention.
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The outstanding ratification is expected to be obtained shortly and the
Convention will likely enter into force in 2016.
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